Plastic pull tab to metal tear strip connection with plug gripping feature



July 20, 1965 J. HENCHERT 3,195,766,

PLASTIC PULL TAB TO METAL TEAR STRIP CONNECTION WITH PLUG GRIPPING FEATURE Original Filed Feb. 10. 1961 INVENTOR Joan Hana-152T United States Patent PLASTIC PULL TAB T0 METAL TEAR STRIP CON- NECIION WITH PLUG GRIIPING FEATURE John Henchert, Oak Park, Ill, assignor to Continental Can Company, Inc., New York, N.Y;, a corporation of New York Original application Feb. 10, 1961, Ser. No. 88,473, now Patent No. 3,151,766, dated Get. 6, 1364. Divided and this application June 19, 1963, Ser. No. 289,069

2 Claims. (Cl. 220-54) This application is a division of my copending application Serial No. 88,473, filed February 10, 1961.

This invention relates in general to new and useful improvements in means for opening containers, such as cans, and more particularly is directed to a novel tear strip arrangement for containers including metal can ends wherein a container may be opened by merely grasping a pull tab attached to a tear strip and removing the tear strip to thereby remove a panel of the container.

One of the primary objects of this invention is to provide a novel tear strip and pull tab combination wherein the pull tab is firmly anchored to one end of the tear strip and is of a greater width than the tear strip whereby the pull tab rests upon the associated container member on opposite sides of the tear strip to reinforce the tear strip at its starting end to eliminate the accidental rupture of the container member at the starting end of the tear strip.

Another object of this invention is to provide a novel tear strip and'pull tab arrangement wherein the pull tab is provided with an end which is merely passed through an opening in the starting end of the tear strip and is thus interlocked with the tear strip, with the mechanical connection between the tear strip and the pull tab being sufiiciently great to prevent the accidental removal of the pull tab from the tear strip during a tear strip removal operation.

A still further object of this invention is to provide a novel mechanical connection between a palstic pull tab and a metal tear strip wherein the tear strip is provided with an opening into which a plug portion of the pull tab is snapped and the connection between the plug portion and the adjacent metal of the tear strip being such that as the pressure on the plug portion for removal thereof is increased, the gripping of the plug by the metal of the tear strip is likewise increased to prevent the separation or" the tear strip and the pull tab.

This invention also proposes to provide means to facilitate the starting of the tearing of a tear strip from the adjacent metal whereby the tear strip is provided with a generally semi-circular end portion which is scored more I U deeply than side edge portions of the tear. strip, whereby a lesser starting force is required to rupture the tear strip along the score lines.

With the above and other objects in view that will hereinafter appear, the nature of the invention will be more clearly understood by reference to the following detailed description, the appended claims and the several views illustrated in the accompanying drawings:

In the drawings:

FIGURE 1 is a perspective view of an upper portion of a can having a metal can end which is provided with a tear strip and pull tab in accordance with this invention.

FIGURE 2 is a perspective view similar to FIGURE 1 and shows the tear strip partially removed.

FIGURE 3 is an enlarged fragmentary perspective view showing further the general details of the tear strip and pull tab combination.

FIGURE 4 is an enlarged fragmentary vertical sectional view taken along the line 4-4 of FIGURE 3, and

"ice

shows the specific details of the connection between the pull tab and the tear strip.

FIGURE 5 is an enlarged'fragmentary transverse vertical sectional view takenalong the line 55 of FIGURE 3 and-shows further the details of the connection between the pull tab and'tear strip, including the fact that the pull tab overlies the metal can end on opposite sides of the tear strip to prevent the accidental rupturing of the can end along the outline of the tear strip by a downward pressure.

FIGURE 6 is a fragmentary plan view showing the general outline of the tear strip at the starting end thereof and the formation of the score lines defining the same.

FIGURE 7 is an enlarged fragmentary vertical-sectional view taken along the line 77 of FIGURE 6, and shows the specific arrangement of the scores in the various portions of the metal can end along the outline of the tear strip.

Reference'is first made to FIGURES l, 2 and 3, wherein there is illustrated a conventional type of can which is generally referred to by the numeral 20, and which includes a can body 21 and a can end 22. The can end 22 is preferably formed of a light gauge metal, and it is desirable that the metal be easily rupturable. As a result, normally the can end22 will-be formed of aluminum, al though the usual metals employed in the making of the can ends may be utilized. The can end 22 is secured to the can body 21 by a conventional seam 23. The can 20 is illustrated and described only to set forth one environment of the invention. The present invention is not restricted to cans, but may be used in all types of containers, etc, where it is desired to remove a portion thereof without utilizing any opening equipment, such as a can opener in the case of a can.

Reference is now made to FIGURE 3 in particular, wherein the can end 22 is illustrated as having a circumferential tear strip 24 which is defined by a pair of score lines-25, 26 with the score line 25 being disposed outermost and being disposed adjacent the seam 23 so that when the tear strip 24 is removed, substantially the ehtire can end-22 within theseam 23 will beremoved. The score lines 25, 26 are disposed generally in concentric relation for themost part of their lengths and the score line 26 generally defines an inner panel 27 The starting endof the tear strip 24 is provided with a pull tab, which is generally referred to by the numeral 28. The pull tab 28, as is best shown in FIGURES 4 and '5, is formed of a resilient deformable plastic.

The starting end of the tear strip 24 is provided with anopening 29 therethrough defined by an annular flange 30. The flange 3t first extends downwardly and inwardly and is then turnedinwardly at agreater angle, as at 31.

The pull tab 28 is provided with a hollow or tubular plug portion 32 adjacent one end thereof. The plug portion extends downwardly from the main part of the pull tab and is provided adjacent its lower end with an annular rib 33 having an upwardly flaring lower portion 34 and a generally square cut upper shoulder 35. The flared lower portion 34 facilitates the insertion of the plug portion 32 through the opening 29 and the engagement of the lower edge of the flange 30 with the shoulder 35 prevents the accidental withdrawal of the plug portion 32 through the opening 29. The relationship of the plug portion 32 with respect to the flange is such to assure a sealing of the opening 29 at all times even when a prod uct is packaged in the can 29 under pressure. The lower portion of the annular flange 30 being inwardly directed, when an upward pull is exerted on the pull tab 28, the lower portion of the flange 30 will be cammed inwardly to more firmly grip the plug portion 32 and thus prevent accidental removal of the pull tab 28 from the tear strip 24.

Referring now. to FIGURE 4 in' particular, it will be seen that the pull tab 28 has an elongated body portion 36 which is slightly thinner than that portion of the pull tab fromwhich' the plugportion 32 depends. The body portion is provided adjacent the end thereof remote from the plug portion 32 with an upper transverse rib 37 and a lower transverse rib 38 to facilitate the grasping of the pull tab 28 and the exerting of a tear strip tearing and removal force thereon. It is to be noted that the rib 38 is of a thickness so as to rest upon the upper surface of the can end 22 in the normal at rest position of the pull tab.

Reference is now made to FIGURES 6 and 7, wherein the details'of the score lines defining the various tear strips at the starting end of each tear strip, are shown. For identification purposes only, the partial can end illustrated in FIGURE 6 willbe considered to be the can end 22, and the tear strip, the tear strip 24. As was previously described, the tear strip 24'is defined by a pair of score lines 25, 26. As is best illustrated in FIGURE 7, these score lines 25, 26 are relatively shallow. The score lines 25 and 26 will preferably be of a depth so that the remaining metal to be torn in the removal of the tear strip 24 will have a thickness of 0.003 inch. The ends of the score lines 25, 26 are connected together by a generally semi-circular score line 102 which has a greater basewidth and is ofa greater depth, as is best illustrated in FIGURES 6 and 7. The depth of the score line 102 will be such that in most instances, the remaining thickness of inetal to be torn will range between 0.001 inch and 0.0015 inch. By making the score line 102 much deeper than the score lines 25, 26, it will be readily apparent that a sharp upward pull on the starting end of the tear strip 24 by means of the pull tab 28 will result in the rupturing of the metal of the can end 22 along the score line 102. Once the initial rupturing has been accomplished the tear strip 24 may. be removed by continuously exerting an upward pull thereon with the tear strip 24'being torn from the can end 22 along the tear lines 25, 26..

The advantage of the relatively deep score line 102 coupled with the supporting feature of the individual pull tab is obvious. Applicant has made theinitially torn portion of the can end of suflicient weakness to facilitate the ease of tearing the starting end of the tear strip therefrom. On the other hand, by making each pull tab of a sufiicient width to engage the can end outwardly of the tear strip, the tear strip is prevented from deflecting inwardly due to any accidental force exerted thereon, whereby the-can 20 would be opened prematurely.

From the foregoing, it will be seen that novel and advantageous provision has been made for carrying out the desired end. However, attention is again directed to the fact that variations may be made in the examples of the invention disclosed herein without departing from the spirit and scope of the invention, as defined in the appended claims.

I claim:

1. A tear strip assembly comprising a panel, a tear strip defined in said panel by spaced weakening lines in said panel, said tear strip having a starting end defined at least in part by a weakening line of lesser strength than adjacent portions of said spaced weakening lines, and a pull tab overlying and connected to said tear strip starting end for facilitating the removal of said tear strip, said pull tab being of a greater width than the underlying portion of said tear strip and resting on said panel outwardly of said tear strip to resist accidental rupturing of said panel by inward displacement of said tear strip starting end, said tear strip having an opening therethrough and said pull tab having a plug portion extending through the tear strip opening and locking behind said tear strip to both directly seal said opening and securesaid pull tab to said tear strip, the tear strip opening being defined by a downwardly directed flange and said plug portion having an annular shoulder locked behind said flange, said plug portion being upwardly flared beneath said shoulder and formed of a resilient deformable pull tab formed of a resilient deformable plastic, said' pull tab having a depending plug portion extending through and sealing the tear strip opening, said plug portion having an upwardly directed shoulder engaged behind said flange to secure said pull tab to said tear strip, the lower portion of said flange being inwardly directed to provide an inwardly directed lower edge engaging said plug portion and being subject to inward movement in response to upward movement of said plug portion to more firmly grip said plug portion, said tear strip being formed in a panel and said pull tab being in the form of an elongated strip having a thick attaching portion from which saidplug portion projects and a thinner grip portion, said grip portion having transverse upper and lower ribs extending thereacross to facilitate gripping thereof, said ribs being spaced from an adjacent end of said pull tab and the lower one of said ribs resting on said panel and supporting said adjacent pull tab -end in elevation relative to said panel to facilitate the initial lifting of said pull tabj References Cited by the Examiner UNITED STATES PATENTS 2,029,329 2/ 36 Ljungstrom et al. 220-52 2,907,489 10/ 59 Taylor 220-38.5 2,978,140 4/61 Walsh.

3,032,226 5/62 Terwilliger 215-46 THERON EJCONDON, Primary Examiner. 

1. A TEAR STRIP ASSEMBLY COMPRISING A PANEL, A TEAR STRIP DEFINED IN SAID PANEL BY SPACED WEAKENING LINES IN SAID PANEL, SAID TEAR STRIP HAVING A STARTING END DEFINED AT LEAST IN PART BY A WEAKENING LINE OF LESSER STRENGTH THAN ADJACENT PORTIONS OF SAID SPACED WEAKENING LINES, AND A PULL TAB OVERLYING AND CONNECTED TO SAID TEAR STRIP STARTING END FORF FACILITATING THE REMOVAL OF SAID TEAR STRIP, SAID PULL TAB BEING OF A GREATER WIDTH THAN THE UNDERLYING PORTION OF SAID TEAR STRIP AND RESTING ON SAID PANEL OUTWARDLY OF SAID TEAR STRIP TO RESIST ACCIDENTAL RUPTURING OF SAID PANEL BY INWARD DISPLACEMENT OF SAID TEAR STRIP STARTING END, SAID TEAR STRIP HAVING AN OPENING THERETHROUGH AND SAID PULL TAB HAVING A PLUG PORTION EXTENDING THROUGH THE TEAR STRIP OPENING AND LOCKING BEHIND SAID TEAR STRIP TO BOTH DIRECTLY SEAL SAID OPENING AND SECURE SAID PULL TAB TO SAID TEAR STRIP, THE TEAR STRIP OPENING BEING DEFINED BY A DOWNWARLDY DIRECTED FLANGE AND SAID PLUG PORTION HAVING AN ANNULAR SHOULDER LOCKED BEHIND SAID FLANGE, SAID PLUG PORTION BEING UPWARDLY FLARED BENEATH SAID SHOULDER AND FORMED OF A RESILIENT DEFORMABLE PLASTIC TO FACILITATE THE INSERTION OF SAID PLUG PORTION THROUGH THE TEAR STRIP OPENING, SAID FLANGE HAVING AN INWARDLY DIRECTED LOWER PART WHEREBY AN UPWARD PULL ON SAID PLUG PORTION WILL RESULT IN AN INWARD DEFLECTION OF SAID FLANGE AND A FIRMER GRIPPING OF SAID PLUG PORTION. 